Embodiments of the present invention relate to an authentication method in a Near Field Communication (NFC) system or chipset comprising an NFC interface circuit sending and receiving contactless data.
Embodiments of the present invention particularly relate to authenticating a secure processor of the chipset by an NFC component of the chipset. “NFC component” means a controller (microcontroller) connected to an NFC interface circuit.
NFC technology is currently developed by an industrial consortium grouped under the name Forum NFC (http://www.nfc-forum.org). The NFC technology is derived from Radio Frequency Identification (RFID) technology and uses NFC components which may have several operating modes, i.e., a “reader” mode, a “card emulation” mode, and a “device” mode (also referred to as “device-to-device” mode). In the “reader” mode, the NFC component operates like a standard RFID reader to read- or write-access an RFID chip (e.g., chip card or contactless tag). The NFC component emits a magnetic field, sends data by modulating the amplitude of the magnetic field, and receives data by load modulation and inductive coupling. In the “emulation” mode, described in commonly assigned patent EP 1 327 222, the NFC component operates passively like a transponder to communicate with another reader and to be seen by the other reader as an RFID chip. The component does not emit any magnetic field, receives data by demodulating a magnetic field emitted by the other reader, and sends data by modulating the impedance of its antenna circuit (load modulation). In the “device” mode, the component must match another NFC component located in the same operating mode, and each NFC component alternately goes into a passive state (without field emission) to receive data and into an active state (with field emission) to send data.
In addition to these three operating modes (other operating modes could be designed in the future), an NFC component may implement several contactless communication protocols and is capable, for example, of exchanging data according to the ISO 14443-A protocol, the ISO 14443-B protocol, the ISO 15693 protocol, or the like. Each protocol defines a frequency of emission of the magnetic field, a modulation method for modulating the amplitude of the magnetic field to send data in active mode, and a load modulation method by inductive coupling to send data in passive mode. Therefore, an NFC component is a multimode and multi-protocol device. The applicant markets, for example, an NFC component under the name “MicroRead”.